3,149 research outputs found

    The decays B→Ψ(2S)π(K),ηc(2S)π(K)B\to \Psi(2S)\pi(K),\eta_c(2S)\pi(K) in the pQCD approach beyond the leading-order

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    Two body BB meson decays involving the radially excited meson ψ(2S)/Ξ·c(2S)\psi(2S)/\eta_c(2S) in the final states are studied by using the perturbative QCD (pQCD) approach. We find that: (a) The branching ratios for the decays involving KK meson are predicted as Br(B+β†’Οˆ(2S)K+)=(5.37βˆ’2.22+1.85)Γ—10βˆ’4,Br(B0β†’Οˆ(2S)K0)=(4.98βˆ’2.06+1.71)Γ—10βˆ’4,Br(B+β†’Ξ·c(2S)K+)=(3.54βˆ’3.09+3.18)Γ—10βˆ’4Br(B^+\to\psi(2S)K^+)=(5.37^{+1.85}_{-2.22})\times10^{-4}, Br(B^0\to\psi(2S)K^0)=(4.98^{+1.71}_{-2.06})\times10^{-4}, Br(B^+\to\eta_c(2S)K^+)=(3.54^{+3.18}_{-3.09})\times10^{-4}, which are consistent well with the present data when including the next-to-leading-order (NLO) effects. Here the NLO effects are from the vertex corrections and the NLO Wilson coefficients. The large errors in the decay B+β†’Ξ·c(2S)K+B^+\to\eta_c(2S)K^+ are mainly induced by using the decay constant fΞ·c(2S)=0.243βˆ’0.111+0.079f_{\eta_c(2S)}=0.243^{+0.079}_{-0.111} GeV with large uncertainties. (b) While there seems to be some room left for other higher order corrections or the non-perturbative long distance contributions in the decays involving Ο€\pi meson, Br(B+β†’Οˆ(2S)Ο€+)=(1.17βˆ’0.50+0.42)Γ—10βˆ’5,Br(B0β†’Οˆ(2S)Ο€0)=0.54βˆ’0.23+0.20Γ—10βˆ’5Br(B^+\to\psi(2S)\pi^+)=(1.17^{+0.42}_{-0.50})\times10^{-5}, Br(B^0\to\psi(2S)\pi^0)=0.54^{+0.20}_{-0.23}\times10^{-5}, which are smaller than the present data. The results for other decays can be tested at the running LHCb and forthcoming Super-B experiments. (c) There is no obvious evidence of the direct CP violation being seen in the decays Bβ†’Οˆ(2S)Ο€(K),Ξ·c(2S)Ο€(K)B\to \psi(2S)\pi(K), \eta_c(2S)\pi(K) in the present experiments, which is supported by our calculations. If a few percent value is confirmed in the future , it would indicate new physics definitely.Comment: 11 pages, 3 figures. arXiv admin note: text overlap with arXiv:1705.0052

    Three body radiative decay Bs→ϕKˉ0γB_s\to \phi \bar K^0 \gamma in the PQCD approach

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    We study the three body radiative decay Bsβ†’Ο•KΛ‰0Ξ³B_s\to \phi \bar K^0 \gamma by introducing the Ο•K\phi K pair distribution amplitudes (DAs) in the perturbative QCD approach. This nonperturbative inputs, the two meson DAs, is very important to simplify the calculations. Besides the dominant electromagnetic penguin operator O7Ξ³O_{7\gamma}, the subleading contributions from chromomagnetic penguin operator O8gO_{8g}, quark-loop corrections and annihilation type amplitudes are also considered. We find that the branching ratio for the decay Bsβ†’Ο•KΛ‰0Ξ³B_s\to \phi \bar K^0 \gamma is about (9.26βˆ’1.61βˆ’3.86βˆ’0.49+1.79+3.12+0.64)Γ—10βˆ’8(9.26^{+1.79+3.12+0.64}_{-1.61-3.86-0.49})\times10^{-8}, which is much smaller compared with that for the decay B0β†’Ο•K0Ξ³B^0\to \phi K^0\gamma. It is mainly because that the former decay induces by bβ†’dΞ³b\to d\gamma with small CKM matrix element being proportional to Ξ»3\lambda^3. The prediction for the direct CP asymmetry is ACPdir(Bsβ†’Ο•KΛ‰0Ξ³)=(βˆ’4.1βˆ’0.6βˆ’1.2βˆ’0.1+0.4+1.7+0.2)%A^{dir}_{CP}(B_s\to \phi \bar K^0 \gamma)=(-4.1^{+0.4+1.7+0.2}_{-0.6-1.2-0.1})\%, which is well consistent with the result from the U-spin symmetry approach. we also predict the Bsβ†’Ο•KΛ‰0Ξ³B_s \to\phi \bar K^0\gamma decay spectrum, which exhibits a maximu at the Ο•K\phi K invariant masss around 1.95 GeV.Comment: 17 pages,6 figures, Accepted for publication in EPJ
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